Sens. Jim Inhofe and Tom Coburn are among 10 Republican senators who sent a letter to EPA Administrator Lisa Jackson on Friday about a report that linked hydraulic fracturing to groundwater contamination.

Hydraulic fracturing, which has been used for more than 50 years on oil and gas wells, involves pumping water, sand and chemicals into a well to create cracks in shale formations.

The industry and its supporters have argued that federal regulation is unnecessary because states have been doing the job well for decades and that there has not been a single documented case of groundwater contamination.

Sen. Lisa Murkowski, R-Alaska, one of the 10 Republican senators who signed the letter on Friday, said in a statement, “The EPA appears to have jumped to the conclusion that fracking is to blame for contaminating groundwater based solely on preliminary data that has not been fully vetted.

“Given the significance and potential impacts this could have on our nation's energy supplies, it's crucial that the agency makes sure it has all of the facts before drawing any formal conclusions or making any policy decisions."

The EPA is in the midst of a separate, comprehensive review of the potential effects of fracking on water.